U.S. patent application number 11/738334 was filed with the patent office on 2008-10-23 for method and apparatus for registering and maintaining registration of a medium in a content applicator.
This patent application is currently assigned to INTERMEC IP CORP.. Invention is credited to Kevin Conwell, Kathy McCready, Xiaonong Qian.
Application Number | 20080259111 11/738334 |
Document ID | / |
Family ID | 39871754 |
Filed Date | 2008-10-23 |
United States Patent
Application |
20080259111 |
Kind Code |
A1 |
McCready; Kathy ; et
al. |
October 23, 2008 |
METHOD AND APPARATUS FOR REGISTERING AND MAINTAINING REGISTRATION
OF A MEDIUM IN A CONTENT APPLICATOR
Abstract
A content applicator receives a continuous medium and applies
content to segments of the continuous medium. The content
applicator includes a sensor array, a controller subsystem, and a
print station. The sensor array scans the continuous medium as the
continuous medium moves along a medium transport pathway. The
controller subsystems receives scan information from the sensor
array and uses the scan information to establish and maintain
registration between the continuous medium and the print
station.
Inventors: |
McCready; Kathy; (Bothell,
WA) ; Conwell; Kevin; (Fairfield, OH) ; Qian;
Xiaonong; (Mukilteo, WA) |
Correspondence
Address: |
SEED INTELLECTUAL PROPERTY LAW GROUP PLLC
701 FIFTH AVENUE, SUITE 5400
SEATTLE
WA
98104-7092
US
|
Assignee: |
INTERMEC IP CORP.
Everett
WA
|
Family ID: |
39871754 |
Appl. No.: |
11/738334 |
Filed: |
April 20, 2007 |
Current U.S.
Class: |
347/16 |
Current CPC
Class: |
B41J 11/42 20130101;
B41J 3/4075 20130101; B41J 3/44 20130101 |
Class at
Publication: |
347/16 |
International
Class: |
B41J 29/38 20060101
B41J029/38 |
Claims
1. A content applicator for applying content to a continuous
medium, the content applicator comprising: a print station having a
print head disposed proximal to a medium transport pathway for
having the continuous medium pass therethrough, the print head
configured to print on the continuous medium; an array of
electromagnetic sensors disposed proximal to the medium transport
pathway configured to scan a portion of the continuous medium; a
controller subsystem in communication with the electromagnetic
sensors and configured to determine a speed for the scanned portion
of the continuous medium, wherein the controller subsystem adjusts
the speed of the continuous medium to maintain registration of the
continuous medium with the print station.
2. The content applicator of claim 1, wherein the array of
electromagnetic sensors includes: a first sensor bundle having a
first electromagnetic source and a first electromagnetic detector,
the first electromagnetic source aligned to illuminate a first
portion of the continuous medium in the medium transport pathway,
the first electromagnetic source aligned to receive electromagnetic
radiation from the first portion of the continuous medium; and a
second sensor bundle having a second electromagnetic source and a
second electromagnetic detector, the second electromagnetic source
aligned to illuminate a second portion of the continuous medium in
the medium transport pathway, the second electromagnetic source
aligned to receive electromagnetic radiation from the third portion
of the continuous medium, wherein the second and third portions of
the continuous medium are approximately opposed.
3. The content of claim 2, wherein the first electromagnetic source
emits electromagnetic radiation within a first range of
frequencies, the second electromagnetic source emits
electromagnetic radiation within a second range of frequencies.
4. The content of claim 3, wherein the first range of frequencies
and second range of frequencies are non-overlapping.
5. The content applicator of claim 2, wherein the array of
electromagnetic sensors includes: a wireless communication device
interface.
6. The content applicator of claim 1, further comprising: means for
controllably exerting a tension on the continuous medium, wherein
the controller subsystem controllably exerts the tension on the
continuous medium to maintain registration of the continuous
medium.
7. The content applicator of claim 6 wherein the means for
controllably exerting a tension on the continuous medium comprises:
a first driven member at a first end of the medium transport
pathway configured to receive a roll of continuous medium and
configured provide the continuous medium to the medium transport
pathway, the first driven member controlled by the controller
subsystem, wherein the first driven member unwinds the continuous
medium from the roll at a first rate determined by controller
subsystem controls.
8. The content applicator of claim 7 wherein the first driven
member winds the continuous medium onto the roll at a second rate
determined by controller subsystem controls.
9. The content applicator of claim 6 wherein the means for
controllably exerting a tension on the continuous medium comprises:
a second driven member at a second end of the medium transport
pathway configured to receive a roll and configured receive the
continuous medium from the medium transport pathway, the second
driven member controlled by the controller subsystem, wherein the
second driven member winds the continuous medium onto the roll at a
first rate determined by controller subsystem controls.
10. The content applicator of claim 9 wherein the second driven
member unwinds the continuous medium from the roll at a second rate
determined by controller subsystem controls.
11. The content applicator of claim 6 wherein the means for
controllably exerting a tension on the continuous medium comprises:
a ribbon extending between a let-out spindle and a take-up spindle
and interposing the print head and the medium transport pathway,
wherein the let-out spindle and the take-up spindle are controlled
by the controller subsystem apply a variable tension to the ribbon,
wherein during printing by the print head the ribbon engages the
continuous medium and the tension applied to the ribbon is such
that the registration of the continuous medium is maintained.
12. The content applicator of claim 1, further comprising: a platen
roller disposed proximal to the medium transport pathway opposite
the print head, a movement of the platen roller controlled by the
controller subsystem, wherein during printing by the print head,
the print head and the platen roller exert a pressure on the
continuous medium, wherein the controller subsystem varies the
pressure such that the registration of the continuous medium is
maintained.
13. The content applicator of claim 1, further comprising: a roller
disposed proximal to the medium transport pathway such that the
roller engages the continuous medium, the roller having a variable
rate of rotation that is controlled by the controller subsystem
such that the registration of the continuous medium is
maintained.
14. The content applicator of claim 13 wherein the roller steps at
a generally uniform rate and the controller subsystem varies the
rate of rotation of the roller by varying the size of the step.
15. The content applicator of claim 13 wherein the roller steps,
each step being approximately the same, and the controller
subsystem varies the rate of rotation of the roller by varying a
time between steps.
16. The content applicator of claim 13 wherein the roller rotates
continuously without stepping.
17. A method of controlling a content applicator, the method
comprising: receiving a first set of scan information from a scan
of a portion of a label in a continuous medium received by the
content applicator, the continuous medium having a number of
labels; determining a scan location by comparing the first set of
scan information to a reference scan profile, the reference scan
profile corresponding to a scan of a given label; and changing a
rate at which the continuous medium moves through a print station
of the content applicator based upon the determined scan
location.
18. The method of claim 17, further comprising: acquiring medium
knowledge for the continuous medium from the continuous medium;
determining settings for the content applicator based upon the
acquired medium knowledge; and establishing initial registration of
the continuous medium with a print head based upon the acquired
medium knowledge.
19. The method of claim 18 wherein acquiring medium knowledge
includes: scanning a length of the continuous medium, the scanned
length including at least one label; and generating a reference
profile from the scanned length of the continuous medium.
20. The method of claim 18 wherein acquiring medium knowledge
includes: interrogating a wireless communication device carried by
the continuous medium; and receiving at least a portion of the
acquired knowledge from the wireless communication device.
21. The method of claim 17 wherein changing a rate includes:
varying a rate of rotation of a roller.
22. The method of claim 21 wherein varying the rate of rotation
includes: varying a step size of the roller.
23. The method of claim 21 wherein varying the rate of rotation
includes: varying a time between which the roller steps.
24. The method of claim 17, further comprising: applying a variable
tension to the continuous medium.
25. The method of claim 24 wherein applying a variable tension to
the continuous medium comprises: adjusting a rate at which a
spindle having a roll of continuous medium thereon rotates.
26. A content applicator for applying content to a continuous
medium, the content applicator comprising: a print station having a
print head disposed proximal to a medium transport pathway for
having the continuous medium pass therethrough, the print head
configured to print on the continuous medium; an array of
electromagnetic sensors disposed proximal to the medium transport
pathway configured to scan a portion of the continuous medium; a
controller subsystem in communication with the electromagnetic
sensors and configured to determine at least a portion of a first
profile for a label included in the scanned portion of the
continuous medium and to use at least the portion of the profile to
maintain registration of the continuous medium with the print
station.
27. The content applicator of claim 26, further comprising: a
memory having a reference profile stored therein, wherein the
controller subsystem compares a reference profile with the first
stored profile.
28. The content applicator of claim 27 wherein the controller
subsystem scans a first segment of the continuous medium to
generate the reference profile.
29. The content applicator of claim 27 wherein the controller
subsystem determines a current location of a label relative to a
sensor bundle of the sensor array based upon scan information from
the sensor bundle and the reference profile.
30. The content applicator of claim 27 wherein the controller
subsystem determines a location of a transition edge of a label
relative to a sensor bundle of the sensor array based upon scan
information from the sensor bundle and the reference profile.
31. The content applicator of claim 30 wherein the transition edge
is a leading edge or a trailing edge of the label.
32. The content applicator of claim 30 wherein the transition edge
is between a leading edge and a trailing edge of the label.
33. The content applicator of claim 30 wherein the transition edge
corresponds to a change in color.
34. The content applicator of claim 30 wherein the transition edge
corresponds to circuitry for a wireless communication device.
Description
BACKGROUND
[0001] 1. Field
[0002] This disclosure is generally related to the field of
printers, and more particularly related to registration of
continuous medium in a printer.
[0003] 2. Description of the Related Art
[0004] Today, on-demand printing frequently involves an on-demand
printer printing specific information or content on a print medium,
such as a label, and may involve applying the printed medium to an
item. In some situations, the item might be one item in a series of
items such as an item in an assembly line. In that case, the
on-demand printer and the assembly line may be synchronized such
that the printed medium can be applied to the item as the item
passes the on-demand printer. The print medium used in an on-demand
printer may be a continuous medium such as a roll of labels carried
on a releasable liner. The printed labels may be peeled from the
releasable liner and adhered to items. However, if the continuous
medium, such as a label roll, is not properly registered with the
on-demand printer, then content printed on the labels of the
continuous medium may be misaligned or some or all of the content
that should have been printed on a label might not be printed on
the label, e.g., the printed content might extend across
labels.
[0005] In addition, there are many varieties of print media
including many types of continuous print media. For example, label
rolls may come in different sizes, or they may come with different
face stock, or they come with a wireless communication device such
as Radio Frequency Identifier (RFID) device. Typically, an
on-demand printer is manually configured to use one variety of
continuous medium and then re-configured to use another variety of
continuous medium. For example, the on-demand printer might be
configured to use one type of marker such as ink, ribbon, or the
like on a first face stock and a different type of maker on a
second face stock.
[0006] There is a need for a printer that may sense a print medium
and automatically reconfigure internal settings. In addition, there
exists a need for a printer that may properly register a continuous
medium, and similarly, there exists a need for a printer that may
maintain proper registration of a continuous medium.
BRIEF SUMMARY
[0007] In one aspect, a content applicator for applying content to
a continuous medium comprises a print station, an array of
electromagnetic sensors, and a controller subsystem. The print
station has a print head disposed proximal to a medium transport
pathway. The continuous medium passes through the medium transport
pathway, and the print head is configured to print on the
continuous medium. The array of electromagnetic sensors is disposed
proximal to the medium transport pathway and is configured to scan
a portion of the continuous medium. The controller subsystem is in
communication with the electromagnetic sensors and is configured to
determine a speed for the scanned portion of the continuous medium,
wherein the controller subsystem adjusts the speed of the
continuous medium to maintain registration of the continuous medium
with the print station.
[0008] In another aspect, a method of controlling a content
applicator includes receiving a first set of scan information from
a scan of a portion of a label in a continuous medium received by
the content applicator, the continuous medium having a number of
labels; determining a scan location by comparing the first set of
scan information to a reference scan profile, the reference scan
profile corresponding to a scan of a given label; and changing a
rate at which the continuous medium moves through a print station
of the content applicator based upon the determined scan
location.
[0009] In another aspect, a content applicator for applying content
to a continuous medium comprises a print station, an array of
electromagnetic sensors, and a controller subsystem. The print
station has a print head disposed proximal to a medium transport
pathway. The continuous medium passes through the medium transport
pathway, and the print head is configured to print on the
continuous medium. The array of electromagnetic sensors is disposed
proximal to the medium transport pathway and is configured to scan
a portion of the continuous medium. The controller subsystem is in
communication with the electromagnetic sensors and is configured to
determine at least a portion of a first profile for a label
included in the scanned portion of the continuous medium and to use
at least the portion of the profile to maintain registration of the
continuous medium with the print station.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0010] In the drawings, identical reference numbers identify
similar elements or acts. The sizes and relative positions of
elements in the drawings are not necessarily drawn to scale. For
example, the shapes of various elements and angles are not drawn to
scale, and some of these elements are arbitrarily enlarged and
positioned to improve drawing legibility. Further, the particular
shapes of the elements as drawn, are not intended to convey any
information regarding the actual shape of the particular elements,
and have been solely selected for ease of recognition in the
drawings.
[0011] FIG. 1 is a block diagram of a content applicator according
to one illustrated embodiment.
[0012] FIG. 2 is a block diagram of a sensor array of the content
applicator of FIG. 1 according to one illustrated embodiment.
[0013] FIG. 3 is a block diagram of print station of the content
applicator of FIG. 1 according to one illustrated embodiment.
[0014] FIG. 4 is a block diagram of a controller subsystem of the
content applicator of FIG. 1 according to one illustrated
embodiment.
[0015] FIG. 5A is a top view of a continuous medium according to
one illustrated embodiment.
[0016] FIG. 5B is a side view of the continuous medium of FIG. 5A
according to one illustrated embodiment.
[0017] FIG. 6 is a scan profile of the continuous medium of FIGS.
5A and 5B according to one illustrated embodiment.
[0018] FIG. 7A is a top view of a continuous medium having a
wireless communication device according to one illustrated
embodiment.
[0019] FIG. 7B is a side view of the continuous medium of FIG. 7A
according to one illustrated embodiment.
[0020] FIG. 8 is a scan profile of the continuous medium of FIGS.
7A and 7B according to one illustrated embodiment.
[0021] FIG. 9 is a flow diagram showing a method employed to
process a continuous medium according to one embodiment.
[0022] FIG. 10 is a flow diagram showing a method employed to
acquire a reference scan profile according to one embodiment.
[0023] FIG. 11 is a flow diagram showing a method employed to
process a continuous medium according to one embodiment.
[0024] FIG. 12 is a flow diagram showing a method employed to
process a continuous medium according to one embodiment.
DETAILED DESCRIPTION
[0025] In the following description, certain specific details are
set forth in order to provide a thorough understanding of various
disclosed embodiments. However, one skilled in the relevant art
will recognize that embodiments may be practiced without one or
more of these specific details, or with other methods, components,
materials, etc. In other instances, well-known structures
associated with systems and methods for handling media, printing,
and forming and/or applying labels and the like have not been shown
or described in detail to avoid unnecessarily obscuring
descriptions of the embodiments.
[0026] Unless the context requires otherwise, throughout the
specification and claims which follow, the word "comprise" and
variations thereof, such as "comprises" and "comprising" are to be
construed in an open, inclusive sense, that is as "including, but
not limited to."
[0027] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure or
characteristic described in connection with the embodiment is
included in at least one embodiment. Thus, the appearances of the
phrases "in one embodiment" or "in an embodiment" in various places
throughout this specification are not necessarily all referring to
the same embodiment. Furthermore, the particular features,
structures, or characteristics may be combined in any suitable
manner in one or more embodiments.
[0028] As used in this specification and the appended claims, the
singular forms "a," "an," and "the" include plural referents unless
the content clearly dictates otherwise. It should also be noted
that the terms "and" and "or" are generally employed in the sense
including "and/or" unless the content clearly dictates
otherwise.
[0029] The headings and Abstract of the Disclosure provided herein
are for convenience only and do not interpret the scope or meaning
of the embodiments.
[0030] FIG. 1 shows a content applicator 10 according to one
illustrated embodiment. In some embodiments, the content applicator
10 may include a printing device such as, but not limited to, an
ink jet printer, a dot matrix printer, an impact printer, a laser
printer, and/or a thermal printer.
[0031] The content applicator 10 includes a sensor array 12, a
print station 14, a label peeler 16, a medium dispenser 18, and a
medium take-up 20, all of which may be controlled by a controller
subsystem 22. A continuous medium 24 is dispensed from the medium
dispenser 18 and extends along a medium transport pathway 26 to the
medium take-up 20.
[0032] The medium dispenser 18 may include a roll 11 of the
continuous medium 24 mounted on a spindle 19. The spindle 19 may be
driven to cause the roll 11 to rotate clockwise and/or
counter-clockwise and thereby wind and unwind the continuous medium
24. Similarly, the medium take-up 20 may include a roll 13 mounted
on a spindle 21, and the spindle 19 may be driven to cause the roll
13 to rotate counter-clockwise and/or clockwise and thereby wind
and unwind the continuous medium 24.
[0033] The continuous medium 24 defines a bottom face 29 and an
opposed top face 31. A number of labels 30 form at least a portion
of the top face, and a release liner 28 forms at least a portion of
the bottom face 29. The labels 30 are releasably adhered to the
release liner by an adhesive layer (not shown), for example, a
pressure sensitive adhesive layer.
[0034] Each one of the labels 30 extends between opposed leading
edge 32 and trailing edge 34 of the respective label 30. In the
embodiment illustrated, the labels 30 do not abut. Instead, the
labels 30 are disposed on the release liner 28 such that there is a
gap 36 between adjacent labels 30. The labels 30 and the portions
of the release liner 28 that are exposed in gap regions 36 define
at least a portion of the top face 31 of the continuous medium 24.
Each one of the labels 30 includes a print region 38 on which the
print station 14 applies indicia.
[0035] The sensor array 12 scans the continuous medium 24 as the
continuous medium 24 passes along the medium transport pathway 26.
In some embodiments, the sensor array 12 may be disposed along the
medium transport pathway 26 between the print station 14 and the
label peeler 16. The sensor array 12 provides the controller
subsystem 22 with medium scan information.
[0036] The label peeler 16 removes the labels 30 from the release
liner 28, and applies the labels 30 to target objects (not shown).
In some embodiments, the label peeler 16 may take the form of a
simple bar 17 or structure having an edge that engages the labels
30 at an acute angle. Other embodiments may employ a variety of
more complicated structures to peel or otherwise remove or separate
the labels 30 from the release liner 28. The release liner 28
extends from the label peeler 16 to the medium take-up 20. In some
embodiments, the label peeler 16 may be bypassed or configured such
that the labels 30 are not removed from the release liner 28, and
in that case, the release liner 28 and labels 30 are received by
the take-up 20.
[0037] The controller subsystem 22 receives medium scan information
from the sensor array 22 and uses the medium scan information to
manage advancement (position) and/or the rate of advancement
(speed) of the continuous medium 24. The continuous medium 24 must
be properly registered with the print station 14 and the label
peeler 16 to ensure that the indicia is properly applied to the
print region 38 of each one of the labels 30 and to ensure that
each one of the labels 30 is properly applied to the target objects
(not shown) by the label peeler 16.
[0038] FIG. 2 shows components of the sensor array 12 according to
one illustrated embodiment. The sensor array 12 includes a number
of opposed sensor bundles, which are collectively referenced as 40
and individually referenced as 40a-40c, and a number of non-opposed
sensor bundles, which are collectively referenced as 42 and
individually referenced as 42a-42b.
[0039] The opposed sensor bundles 40 include a number of
electromagnetic sources, collectively referenced as 44 and
individually referenced as 44a-44c, and a corresponding number of
electromagnetic detectors, collectively referenced as 46 and
individually referenced as 46a-46c. A given opposed sensor bundle
40X includes an electromagnetic source 44X and an electromagnetic
detector 46X, where X is a, b, or c. The opposed sensor bundles are
named as such because for each bundle, the respective
electromagnetic source 44 and the respective electromagnetic
detector 46 are disposed on opposite sides of the medium transport
pathway 26 and generally aligned with each other. The
electromagnetic sources 44 emit electromagnetic radiation 48, which
is incident on the continuous medium 24. The electromagnetic
detectors 46 receive electromagnetic radiation 50 from the
continuous medium 24.
[0040] The non-opposed sensor bundles 42 include a number of
electromagnetic sources, collectively referenced as 52 and
individually referenced as 52a-52b and a corresponding number of
electromagnetic detectors, collectively referenced as 54 and
individually referenced as 54a-54b. A given non-opposed sensor
bundle 42X includes an electromagnetic source 52X and an
electromagnetic detector 54X, where X is a or b. The non-opposed
sensor bundles are named as such because for each bundle, the
respective electromagnetic source 52 and the respective
electromagnetic detector 54 are disposed on the same side of the
medium transport pathway 26. The electromagnetic sources 52 emit
electromagnetic radiation 56, which is incident on the continuous
medium 24, and the electromagnetic detectors 54 are arranged to
receive electromagnetic radiation 58 from the continuous medium 24.
In some embodiments, one or more of the sensors bundles 42 may be
arranged such that the electromagnetic source 52 and the
corresponding electromagnetic detector 54 are longitudinally
aligned and transversely offset with respect to the medium
transport pathway 26.
[0041] In some embodiments, the electromagnetic sources 44 and 52
may include sources such as light emitting diodes, lasers, and/or
other electromagnetic sources including non-coherent sources and
non-monochromatic sources. In some embodiments, the electromagnetic
sources 44, 52 may emit electromagnetic radiation over various
portions of the electromagnetic spectrum. As a non-limiting
example, one or more of the electromagnetic sources 44 may emit
light in the infrared portion of the electromagnetic spectrum, and
one or more of the electromagnetic sources 52 may emit light in the
ultraviolet portion of the electromagnetic spectrum and/or visible
light. In other words, the electromagnetic sources can be
individually selected to emit a given wavelength of electromagnetic
radiation such that all of the electromagnetic sources emit the
same wavelength of electromagnetic radiation, or all of the
electromagnetic sources emit different wavelengths of
electromagnetic radiation, or such that some of the electromagnetic
sources emit the same wavelength of electromagnetic radiation and
the other electromagnetic sources emit different wavelengths of
electromagnetic radiation, and/or any combination or permutation
thereof.
[0042] The electromagnetic detectors 46, 54 may include detectors
such as light sensitive diodes and charge-coupled devices (CCDs),
among others. In some embodiments, an array of detectors such as
multiple photodiodes or a CCD array may be associated with one of
the electromagnetic sources 52. The array of detectors may be used
to track the leading edge 32 and/or trailing edge 34 of the labels
30.
[0043] In some embodiments, one or more of the electromagnetic
detectors may detect electromagnetic radiation at a wavelength that
is generally the same as the wavelength of the electromagnetic
radiation emitted from the corresponding electromagnetic source. In
other words, for a given sensor bundle, such as 42a, the
electromagnetic source 52a and the electromagnetic detector 54a may
operate over the same general wavelength band. Alternatively, one
or more of the electromagnetic detectors may detect electromagnetic
radiation different from the electromagnetic radiation emitted the
corresponding electromagnetic source. In other words, for a given
sensor bundle, such as 42b, the electromagnetic source 52b and the
electromagnetic detector 54b may operate over the different
wavelength bands, e.g., the electromagnetic radiation emitted from
the electromagnetic source 52b may cause portions of the continuous
medium 24 to fluoresce at a wavelength different from the emitted
electromagnetic radiation and the electromagnetic source 52b may
detect the fluorescence of the continuous medium 24. Each one of
the electromagnetic detectors 46, 54 is configured to provide an
analog output signal, which corresponds to detected electromagnetic
radiation, to the controller subsystem 22.
[0044] The electromagnetic radiation 50 and 58 from the continuous
medium 24 may include ambient electromagnetic radiation reflected
from the continuous medium 24, and/or the electromagnetic radiation
50 and 58 from the continuous medium 24 may be electromagnetic
radiation due to fluorescence of the continuous medium 24. In
addition, the electromagnetic radiation 58 from the continuous
medium 24 may include incident electromagnetic radiation 56 that is
reflected from the continuous medium 24.
[0045] In some embodiments, the sensor array 12 may include fewer
or more opposed sensor bundles 44, and/or fewer or more non-opposed
sensor bundles 42. In some embodiments, the sensor array may
include one or more non-opposed sensor bundles 44 disposed under
the medium transport pathway 26 such that the bottom face 31 of the
continuous medium 24 is exposed to the sensor bundles 42 underneath
the medium transport pathway 26.
[0046] The non-opposed sensor bundles 40 may be used to detect a
change in height of the continuous medium 24. The dashed line 60
represents an electromagnetic array reflected from one of the
labels 30. When electromagnetic radiation 56 from the
electromagnetic source 52a is incident upon the release liner 28 in
the gap 36, the electromagnetic detector 54a receives the reflected
electromagnetic radiation 58. However, when the electromagnetic
radiation 56 from the electromagnetic source 52a is incident upon a
portion of the label 30, the electromagnetic radiation is reflected
along the path 60 and is not received by the electromagnetic
detector 54a. Thus, the path difference for electromagnetic
radiation reflected from the gap 36 or from the label 30 can be
used to find the gap 36.
[0047] In some embodiments, the opposed sensor bundles 40 may be
used to determine the location of the leading edge 32 and/or the
location of the trailing edge 34. In some embodiments, a change in
intensity and/or frequency of the detected electromagnetic
radiation 50 may be used to determine the location of the leading
edge 32 and/or the trailing edge 34 of the labels 30. For example,
the intensity and/or frequency of detected electromagnetic
radiation 50 may depend upon whether the incident electromagnetic
radiation 48 was transmitted through the release liner 28 and the
gap 36 or whether the incident electromagnetic radiation 48 was
transmitted through the release liner 28 and one of the labels 30.
In some embodiments, either the release liner 28 or the label 30
may fluoresce in response to electromagnetic radiation 48 and/or 50
being incident upon the continuous medium 24. If the release liner
28 fluoresces, then the fluorescence of the release liner 28 at a
different frequency and/or intensity can be used to track the gap
36. On the other hand, if the labels 30 fluoresce, then the
fluorescence of the labels 30 can be used to track the leading edge
32 and/or trailing edge 34 of the labels 30.
[0048] In some embodiments, holes 62 may be formed in the release
liner 28 in proximity to, or abutting, the leading edge 32 and/or
the trailing edge 34 of the labels 30. The intensity of the
detected electromagnetic radiation 50 will increase when the
electromagnetic radiation 48 is incident upon one of the holes 62.
Consequently, the change in intensity of detected electromagnetic
radiation 50 can be used to track the leading edge 32 and/or the
trailing edge 34 of the labels 30.
[0049] In some embodiments, the release liner 28 may carry
transition indicia 64, which may be on the top face 31 of the
continuous medium 24 and/or on the bottom face 29 of the continuous
medium 24. If the transition indicia 64 is on the top face 31, the
transition indicia 64 may be abutting the leading edges 32 and/or
the trailing edges 34 of the labels 30. Alternatively, the
transition indicia 64 may be at a predetermined location relative
to either the leading edge 32 and/or the trailing edge 34. On the
other hand, if the transition indicia 64 is on the bottom face 29
of the continuous medium 24, the transition indicia 64 may be
underneath the leading edge 32 and/or trailing edge 34 of the
labels 30 and/or at a predetermined location relative to either the
leading edge 32 and/or the trailing edge 34. A non-opposed sensor
bundle 42 having an electromagnetic source 52 and an
electromagnetic detector 54 may be used to detect the transition
indicia 64.
[0050] Similarly, a non-opposed sensor bundle 42 that is arranged
such that the electromagnetic source 52 and the electromagnetic
detector 54 are longitudinally aligned and transversely offset can
be used to detect the holes 62. In such a configured non-opposed
sensor bundle, the electromagnetic source 52 and the
electromagnetic detector 54 can be arranged such that incident
electromagnetic radiation 58 is reflected from the continuous
medium 24 as electromagnetic radiation 56. When the incident
electromagnetic radiation 56 is incident upon one of the holes 62,
the intensity of the detected electromagnetic radiation 56
decreases, which allows the non-opposed sensor bundle 42 to detect
the holes 62.
[0051] In some embodiments, the array sensor 12 includes a wireless
communication device interface 66, which is in communication with
the controller subsystem 22. The wireless communication device
interface 66 may be used to sense wireless communication devices
68. Wireless communication devices 68 may be disposed on or in the
labels 30. In addition, the wireless communication device interface
66 may be used to read/write/interrogate wireless communication
devices 68. As a non-limiting example, the wireless communication
device interface 66 may include a radio frequency identification
(RFID) reader/writer or interrogator, and wireless communication
devices 68 may include RFID devices or transponders, for example,
RFID tags. Among other things, information gathered by the wireless
communication device interface 66 is provided to the controller
subsystem 22. The controller subsystem 22 may also provide
information to the wireless communication device interface 66, and
some or all of the information from the controller subsystem 22 may
be provided by the wireless communication device interface 66 to
one or more wireless communication devices 68. Typically, the
wireless communication device interface 66 is arranged proximal to
the medium transport pathway 26 such that the wireless
communication device interface 66 senses the presence of wireless
communication devices 68 as the labels 30 travel along the medium
transport pathway 26.
[0052] In some embodiments, the wireless communication device
interface 66 provides a signal to the controller subsystem 22 when
the wireless communication device interface 66 senses a wireless
communication device 68. Thus, the wireless communication device
interface 66 can be used to detect the presence of wireless
communication devices 68 and to track labels 30 as the labels 30
move along the medium transport pathway 26.
[0053] FIG. 3 shows the print station 14 according to one
illustrated embodiment. The print station 14 includes a print head
67 and a platen roller 69. The print head 67 and the platen roller
69 are arranged on opposite sides of the medium transport pathway
26. The print head 67 has a print side 70 proximal to the medium
transport pathway 26.
[0054] A ribbon 72, such as a thermal transfer ribbon, passes
underneath the print side 70 and extends from a let-out roll 74 to
a take-up roll 76. The let-out roll 74 and the take-up roll 76 are
mounted on spindles 77a and 77b, respectively, which may be driven.
The print side 70 of the print head 67 presses the ribbon 72
against the label 30 so that print indicia may be printed in the
print region 38 of the labels 30. The ribbon 72 is unwound from the
let-out spindle 74 and rewound on the take-up spindle 76. Among
other things, tension in the ribbon 72 may be controlled by the
controller subsystem 22 via the driven spindles 77a and 77b. The
controller subsystem 22 may control tension by increasing or
decreasing torque in one or both of the let-out spindle 74 and/or
take-up spindle 76. The controller subsystem 22 may also control
the rate at which the ribbon 72 is unwound from the let-out spindle
74 and/or the rate at which the ribbon 72 is wound on the take-up
spindle 76.
[0055] The platen roller 69 rotates about an axis 79. Pressure
between the print head 67 and the platen roller 69 causes the
rotation of the platen roller 69 to advance the continuous medium
24 through the print station 14. The controller subsystem 22 may
control the pressure between the print head 67 and the platen
roller 69 and/or the rate of rotation of the platen roller 69. In
some embodiments, the platen roller 69 may rotate in discrete
steps, and the steps may be variable in size. The controller
subsystem 22 may control the rate of stepping and/or the size of
each step, i.e., the amount of rotation. In some embodiments, the
platen roller 69 may rotate continuously at a variable rate. Some
embodiments may apply other types of mechanisms to form indicia,
for example, different types of print heads, which may or may not
include a platen, which may or may not be fixed.
[0056] FIG. 4 shows the controller subsystem 22 according to one
illustrated embodiment. The controller subsystem 22 includes a
processor 78, a memory 80, one or more digital signal processors
(DSPs) 82, and a bus, which connects all of the above. The DSPs 82
receive the analog signals from the sensor array 14 and provide
digital output, which corresponds to the received analog signals,
to the processor 78.
[0057] Among other things, the controller subsystem 22 may maintain
proper registration of the continuous medium 24 by, among other
things, adjusting the rate at which the continuous medium 24 passes
through the content applicator 10. The controller subsystem 22 may
determine a medium advancement rate, i.e., the current rate at
which the continuous medium 24 passes through the content
applicator 10, and compare the current medium advancement rate to a
theoretical or desired rate, and if necessary, the controller
subsystem 22 can make adjustments to the medium advancement rate to
cause the continuous medium 24 to advance faster or slower or to
retract. By controlling the medium advancement rate to reasonably
match the theoretical or desired rate, content applied to the
labels 30 by the print head 67 is correctly positioned and
scaled.
[0058] In some embodiments, each sensor bundle 40a-40c or 42-42b
may be capable of detecting the leading edge 32 or trailing edge 34
on a single label 30. Thus, within the sensor array 12, the same
leading edge 32 or trailing edge 34 on the label 30 may be detected
at multiple scan positions, which are known by the controller
subsystem 22. The controller subsystem 22 may determine the current
position of a label whenever the leading edge 32 or trailing edge
34 of the label is detected by one of the sensor bundles 40, 42.
The resolution in the current position of the label may be limited
by how close adjacent sensors bundles 40,42 may be physically
placed and/or by a separation distance between adjacent scan
positions and/or how fast the controller subsystem 22 is able to
process the information from the sensor array 12. By adopting
multiple sensor bundles 40, 42 in the sensor array 12, a variation
in the medium advancement rate can be detected in higher resolution
in the sense of medium movement length. Whereas, if only one sensor
bundle is used to detect the leading edge 32 and the trailing edge
34 of the same label 30, or to detect the leading edges 32 of
adjacent labels 30, then the resolution is limited by the label
length.
[0059] The memory 80 includes a medium registration logic 86. When
the medium registration logic 86 is executed by the processor 78,
the processor 78 can control the advancement and/or the rate of
advancement of the continuous medium 24 in the content applicator
10. In addition, the processor 78 may control the retraction and/or
the rate of retraction of the continuous medium 24. Among other
things, the processor 78 may control the advancement and/or
retraction of the continuous medium by one or more of the
following: varying the step size of the platen roller 69; varying
the rate at which the platen roller 69 rotates or steps; varying
the direction of rotation of the platen roller 69; varying the
tension in the ribbon 72; varying the pressure between the platen
roller 69 and the print head 67; varying the rate at which the
medium take-up 20 winds the release liner 28; varying the rate at
which the medium dispenser 18 unwinds the continuous medium 24;
varying the torque about the driven spindle 21 of the medium
take-up 20; varying the torque about the driven spindle 19 of the
medium dispenser 18; and varying the tension in the continuous
medium 24. The processor 78 may control such by applying
appropriate drive signals to one or more actuators, for example,
one or more motors, for instance one or more stepper motors coupled
to drive the platen roller 69, spindle 77b and/or spindle 21, or
other drive mechanism.
[0060] In some embodiments, the sensor array 14 may be distributed
in the content applicator 10. For example, the one or more sensor
bundles may be disposed along the medium transport pathway 26
before and after the print station 14. For each one of the sensor
bundles, the processor 78 can then calculate the speed or velocity
of the continuous medium 24 at each respective sensor bundle. If
the calculated velocities of the continuous medium 24 are different
or the differences exceed a threshold, then the continuous medium
24 may be slipping, which may be caused by, among other things,
excessive wear of the platen roller 69. If slipping occurs between
a roller and the continuous medium 24, then the continuous medium
24 is not registered, i.e., labels 30 of the continuous medium 24
are not going to arrive at the print station 14 at the appropriate
time. The processor 78 may attempt to prevent slipping by, among
other things, varying the pressure between the platen roller 69 and
the print head 67, varying the tension in the ribbon 72, and/or
varying the tension in the continuous medium 24. In the event that
slipping does occur, the processor 78 may correct for the slippage
and re-establish registration by, among others, one or more of the
following: varying the step size of the platen roller 69; varying
the rate at which the platen roller 69 rotates or steps; varying
the direction of rotation of the platen roller 69; varying the
tension in the ribbon 72; varying the pressure between the platen
roller 69 and the print head 67; varying the rate at which the
medium take-up 20 winds the release liner 28; varying the rate at
which the medium dispenser 18 unwinds the continuous medium 24;
varying the torque about the driven spindle 21 of the medium
take-up 20; varying the torque about the driven spindle 19 of the
medium dispenser 18; and varying the tension in the continuous
medium 24.
[0061] Among other things, the medium registration logic 86
includes logic for determining the location of the leading edges 32
and/or trailing edges 34 of the labels 30 based upon the signals
from the digital signal processors 82. The medium registration
logic 86 may know the positions (i.e., scan positions) at which
various sensor bundles 40, 42 scan the continuous medium 24 and may
know the distances between various scan positions and/or sensor
bundles 40, 42, and other components and locations in the content
applicator 10 such as, but not limited to, the distance between:
adjacent sensor bundles 40, 42; adjacent scan positions; an edge of
the label peeler 16 that peels the labels 30 from the release liner
28 and one or more of the sensor bundles 40, 42; an edge of the
label peeler 16 that peels the labels 30 from the release liner 28
and one or more of the scan positions; the print head 67 and one or
more of the sensor bundles 40, 42; the print head 67 and one or
more of the scan positions; and an edge of the label peeler 16 that
peels the labels 30 from the release liner 28 and the print head
67.
[0062] The medium registration logic 86 also includes logic for
determining the rate of advancement and/or retraction, i.e., the
speed of the continuous medium 24 and the direction of the
continuous medium 24. In some embodiments, the medium registration
logic includes logic for determining the location of a label based
upon characteristics of the label. For example, the sensor array 12
may detect transitions between different regions in the label, and
the position of the label may be determined based upon the
transitions. Similarly, the sensor bundles 40, 42 may detect
leading edges 32 and/or trailing edges 34, and the position of the
label may be determined based upon the leading edges 32 and/or
trailing edges 34.
[0063] In some embodiments, the medium registration logic 86
includes logic which when executed by the processor 78 may be used
to generate a scan profile for the labels 30 of the continuous
medium 24. The scan profiles can be used to determine the location
of the labels 30 based upon the signals from the digital signal
processors 82. The processor 78, while executing the medium
registration logic 86 may compare the signals from the digital
signal processors 82 with the scan profile to determine which
portion of the scanned label 30 is currently being scanned. Such
information may be used to determine the current position and/or
velocity/speed of the scanned label.
[0064] Sensor calibration may be necessary when determining a
transition edge such as leading edge 32 or trailing edge 34 or
specific top of form (TOF) reference point such as black line 96
(FIG. 5A) for a given label 30. If the sensor bundles 40, 42 of the
sensor array 12 are not calibrated properly, the content applicator
10 might not maintain accurate and reliable registration. Two
methods, among others, may be used to calibrate the sensor bundles
40, 42 such as scan and compare data to a historical profile stored
in memory or generate a learned profile. Both methods may be
initiated automatically, e.g., through an automated sequence of
events, or manually, e.g., by a manual operation by the user.
Calibration may be repeated throughout a roll of continuous medium,
and scan profiles may be modified and updated if necessary to
improve registration. One or more sensor bundles 40, 42 may be used
for calibration. Sensor bundles may be movable or in a permanent
fixed position. Sensor bundles may be positioned before or after
the print station 14. While multiple sensor bundles are not
required for calibration or detecting transition areas, multiple
sensor bundles do provide better resolution of tracking medium
position and medium advancement rates than can be obtained with a
single sensor bundle.
[0065] Each one of the sensor bundles 40, 42 provides an analog
sensor signal(s), which is received by the processor 78 through one
or more digital signal processors (DSPs) 82. The sensor signals may
be filtered or compressed to fit a desired threshold limit. The
medium registration logic 86 may include logic operations or
algorithms that may be applied to a scan profile to determine the
ideal transition edge. A scan may be over a distance corresponding
to a single pitch within a medium, or over a distance covering
multiples of this repeat length. For each scanned label 30, the
scan may also be limited to only a random portion within the
scanned label 30 or may also be limited to only a specific portion
within the scanned label 30. The acquired scan may be compared to a
known historical reference profile or profiles, which enables the
processor 78 to determine which portion of the label 30 was
scanned.
[0066] In some embodiments, a threshold may be calculated. The
processor 78 can then ignore signals above (or below) the
threshold. For example, there may be anomalies within or on a
label, which produce signal anomalies, and/or variations in color,
which produce variations in the signals (as in FIG. 5). Variations
in signals from a sensor bundle 40, 42 may also occur when the
sensor bundle scans a label with wireless communications device 68
such as an RFID antenna, or a label where opacity levels change, or
when the sensor bundle scans a continuous medium 24 having multiple
types of labels 30.
[0067] During automatic calibration, the medium registration logic
86 may select a duty cycle that falls in a middle range for
available sensor gain. But, in some embodiments, the medium
registration logic 86 may be configured to allow a user to manually
adjust/input to sensor amplification in order to achieve a desired
duty cycle. As one non-limiting example, automatic sensor
calibration by the medium registration logic 86 may include a
look-up table and multiple calibration test values. For example,
two of the test values may represent lower and upper threshold
comparator levels, a third value may represents gain, and a fourth
value may represent current drive. These calibration test values
may be automatically set on a test command. The medium registration
logic 86 may then find a drive/gain combination in the look-up
table for a minimum comparator sample and a maximum comparator
sample. The minimum and maximum comparator values are selected to
differ by at least a predetermined number. As another example, a
first test value may represent a comparator value, which should be
within a predetermined range of comparator values. If this first
value is not within the predetermined range of comparator values, a
second test value, which may represent gain, may be changed to
another second test value, and the medium registration logic 86
selects a different first test value. Typically, both the first
test value and the second test value have respective ranges of
value, and if the respective values of both the first test value
and the second test value are outside of their respective ranges,
then there may be a sensing problem.
[0068] In some embodiments, the medium registration logic may be
implemented in firmware that is stored in a memory and that is
executed by a suitable instruction execution system. If implemented
in hardware, as in an alternative embodiment, the medium
registration can be implemented with any or a combination of the
following technologies: a discrete logic circuit(s) having logic
gates for implementing logic functions upon data signals, an
application specific integrated circuit (ASIC) having appropriate
combinational logic gates, a programmable gate array(s) (PGA), a
field programmable gate array (FPGA), etc.
[0069] FIG. 5A shows the top face 31 of the continuous medium 24,
and FIG. 5B shows a face 88 of the continuous medium 24 according
to one illustrated embodiment. The continuous medium 24 includes a
number of labels 30 that are substantially identical and generally
equally separated by a gap 36. Each one of the labels 30 includes a
white region 90, a green region 92, and a blue region 94. A first
black stripe 96a interposes the white region 90 and the green
region 92, and a second black strip 96b interposes the green region
92 and the blue region 94.
[0070] FIG. 6 shows a number of scan profiles 98 according to one
illustrated embodiment. The scan profile 98 has a number of
relatively flat regions 100, 102, 104, and 106, and a number of
steps 108, 110, 112, and 114. The generally flat region 100 is a
minima that corresponds to the gap region 36. The step 108
corresponds to the leading edge 32 and the generally flat region
102 corresponds to the white region 90. The step 110 corresponds to
the first black strip 96a, and the generally flat region 104
corresponds to the green region 92. The step 112 corresponds to the
second black strip 96b, and the generally flat region 106
corresponds to the generally blue region 94. In addition, the step
114 corresponds to the trailing edge 34.
[0071] FIGS. 7A and 7B show a portion of the continuous medium 24
according to another illustrated embodiment as seen from above and
along a face 88, respectively. The continuous medium 24 includes a
number of labels 30 that are substantially identical and generally
equally separated by a gap 36. Each one of the labels 30 includes a
first region 116 and an RFID region 118. In this embodiment, the
color of the first region 116 and the RFID region 118 are the same.
The RFID region 118 includes components and circuitry of an RFID
device (not shown).
[0072] FIG. 8 shows a sequence of scan profiles 120, which
correspond to the portion of the continuous medium 24 of FIGS. 7A
and 7B. In this example, the scan profiles 120 correspond to the
output of one of the opposed sensor bundles 40. The scan profiles
120 include a number of generally flat regions 122, 124, and 126
and a number of steps 128, 130, and 132.
[0073] The generally flat region 122 corresponds to the gap region
36, and the step 130 corresponds to the leading edge 32. The
generally flat region 124 corresponds to the first region 116, and
the generally flat region 126 corresponds to the RFID region 118.
The step 124 corresponds to the transition between the first region
116 and the RFID region 118. The step 128 corresponds to the
trailing edge 34. The output of the opposed sensor bundle 40 is
greatest in the gap region 36 where the continuous medium 24 is the
thinnest, i.e., where the continuous medium 24 consists of the
release liner 28. The output of the opposed sensor bundle 40 drops
when the first region 116 is scanned. Less of the incident
electromagnetic radiation 48 is transmitted through the release
liner 28 and the region 116 of the label 30 than through the
relatively thin release liner 28 in the gap region 36. Similarly,
when the RFID region is scanned, the components and circuitry of
the RFID device interfere with the electromagnetic radiation being
transmitted through the RFID region 118. Consequently, the output
of the opposed sensor bundle 40 drops to the generally flat region
126.
[0074] In some embodiments, a reference scan profile is stored in
the memory 80, and used by the processor 78 to, among other things,
determine registration of the continuous medium 24. In some
embodiments, the memory 80 may include multiple reference scan
profiles of the continuous medium 24. The multiple scan reference
profiles stored in the memory 80 may correspond to scans by
different types of scanning devices, e.g., opposed scanner bundles
40 and non-opposed scanner bundles 42, or by scans done using
different types of electromagnetic sources, or by scans done using
different types of electromagnetic detectors. The processor 78 may
receive scan information from a particular sensor bundle and
compare the scan information to a stored reference profile to
determine which portion of the label is currently being scanned,
and thereby, determine the relative location of the scanned
label.
[0075] FIG. 9 shows an exemplary method, which may be implemented
by the controller subsystem 22, for registering the continuous
medium 24.
[0076] At 134, medium knowledge is acquired. The acquired medium
knowledge enables the controller subsystem 22 to determine the
position of the labels 30 within the sensor array 12 using the
acquired medium knowledge. In some embodiments, the acquired medium
knowledge may be inputted into the content applicator 10 by a user.
For example, the user might input characteristics of the continuous
medium 24 such as, but not limited to, gap size, label length,
label color, presence or absence of RFID devices, presence or
absence of holes 62, and/or presence or absence of transition
indicia 64. In some embodiments, the controller subsystem 22 may
acquire the medium knowledge by generating one or more scan
profiles of a segment of the continuous medium 24. For example, a
segment of the continuous medium 24 may be fed through the sensor
array 12 and scanned. One or more scan profiles may be generated
from the scanned segment, and these scan profiles become the
acquired knowledge upon which reference profiles are based. In some
embodiments, the controller subsystem 22 may acquire medium
knowledge by interrogating one or more RFID devices carried in one
or more labels 30.
[0077] At 136, the acquired knowledge is applied to settings and
operational parameters of the content applicator 10 and to provide
initial registration of the continuous medium 24 with the print
station 14. As an example, the acquired knowledge may be used to
set a desired advance rate for the continuous medium.
[0078] At 138, the continuous medium 24 is advanced (or retracted),
and the portion of the continuous medium 24 within the sensor array
is scanned. The continuous medium 24 is scanned by passing the
continuous medium 24 along the medium transport pathway 26 of the
sensor array 12. The sensor array 12 provides the controller
subsystem 24 with signals corresponding to the outputs of the
electromagnetic detectors 46 and 54.
[0079] At 140, the controller subsystem 22 determines whether the
continuous medium 24 is properly registered. If the registration is
correct, the process returns to 138. On the other hand, if the
registration of the continuous medium is incorrect, the process
continues at 142. At 142, the controller subsystem 22 determines an
adjustment to one or more of the operational settings or
parameters.
[0080] At 142, the adjustment is implemented by the controller
subsystem 22. Adjustments include, but are not limited to, varying
the pressure between the platen roller and the print head, varying
the tension in the continuous medium, varying the tension in the
ribbon, varying the step size of the platen roller, and/or varying
the velocity of the continuous medium through the content
applicator 10.
[0081] FIG. 10 shows a method of acquiring medium knowledge
according to one illustrated embodiment. At 144, a length of
continuous medium is scanned by the sensor array 12. During the
scan, the sensor array 12 provides the controller subsystem 22 with
the outputs of the sensor bundles 40, 42.
[0082] At 146, the controller subsystem 22 determines a reference
point. Among other things, the reference point may be the location
of a gap 36, the location of a hole 62, the location of transition
indicia, and/or the location of the gap 36, as determined by change
in height of the label or change in intensity or frequency of
electromagnetic radiation.
[0083] At 148, the controller subsystem 22 generates a reference
scan profile from the signals provided by the sensor array 12.
Typically, the sensor array or the length of the scan is such that
more than one label 30 has been scanned. In that case, the
controller subsystem 22 processes the scan information to determine
where the output signals from the sensor array starts to repeat. At
150, the controller subsystem 22 stores the reference scan profile
in the memory.
[0084] FIG. 11 shows a method 1100 of controlling registration of
the continuous medium 24 according to one illustrated embodiment.
The process 1100 allows the controller subsystem 22 to constantly
monitor the rate at which the continuous medium 24 advances (or
retracts) through the content applicator 10 and proper registration
may be maintained by adjusting the rate at which continuous medium
24 advances (or retracts).
[0085] At 1102, the process begins. The continuous medium 24 is
feed through the content applicator 10 along the medium transport
pathway 26 from the medium dispenser 18 to the medium take-up
20.
[0086] At 1104, the continuous medium 24 is advanced along the
medium transport pathway 26. The continuous medium 24 may be
advanced (or retracted) in discrete steps, which may be of equal
step size or variable step size, and the time between the discrete
steps may be periodic or variable. In some embodiments, the time
interval between discrete steps may be so small such that the
advancement (or retraction) of the continuous medium 24 may be
effectively continuous. Similarly, in some embodiments, the
advancement (or retraction) of the continuous medium 24 may be
continuous.
[0087] At 1106, a first one of the sensor bundles such as sensor
bundle 42b detects a label 30. The sensor bundle 42b may detect the
leading edge 32 or trailing edge 34 of the label 30 or may detect a
transition in the label 30. When the sensor bundle 42b detects a
specific portion of the label 30 such as the leading edge 32 or
trailing edge 34, a timing measurement begins. The controller
subsystem 22 may start a clock or may record the current time of a
clock.
[0088] At 1108, a second one of the sensor bundles such as sensor
bundle 40b detects the same label 30. The sensor bundle 40b may
detect the leading edge 32 or trailing edge 34 of the label 30 or
may detect a transition in the label 30. When the sensor bundle 40b
detect the same specific portion of the same label 30, the timing
measurement ends. The controller subsystem 22 may stop the clock or
may record the current time of the clock.
[0089] At 1110, the controller subsystem 22 determines the time
difference between when the first and second sensor bundles
detected the same label. Based upon the time difference and the
distance between the first and second sensor bundles, the
controller subsystem 22 determines calculates a current medium
advancement rate for the continuous medium 24.
[0090] At 1112, the controller subsystem 22 determines whether the
current medium advancement rate is acceptable. If the current
medium advancement rate is not within a certain tolerance of a
desired medium advancement rate, then the current medium
advancement rate is unacceptable because registration of the
continuous medium 24 with respect to the print head 67 and/or the
label peeler 16 will be lost.
[0091] If the current medium advancement rate is not acceptable,
the process continues at 1114. Otherwise, the process continues at
1116. At 1114, the controller subsystem 22 determines a new medium
advancement rate. The new medium advancement rate may speed up,
slow down, and/or reverse the direction of movement of the
continuous medium 24, e.g., retract the continuous medium 24.
[0092] At 1116, the controller subsystem 22 determines whether the
end of the continuous medium 24 has been reached. If the end of the
continuous medium 24 has been reached, the process ends at 1118.
Otherwise, the process returns to 1104, where the medium
advancement rate is used to advance the continuous medium.
[0093] FIG. 12 shows a method 1200 of controlling registration of
the continuous medium 24 according to one illustrated embodiment.
The process 1200 allows the controller subsystem 22 to constantly
monitor rate at which the continuous medium 24 advances (or
retracts) through the content applicator 10. The controller
subsystem 22 may control variations in the rate at which the
continuous medium 24 advances (or retracts) with a high degree of
resolution such that one or more adjustments may be made before a
label traverses the distance of a label length.
[0094] At 1202, the process begins. The continuous medium 24 is
feed through the content applicator 10 along the medium transport
pathway 26 from the medium dispenser 18 to the medium take-up
20.
[0095] At 1204, the continuous medium 24 is advanced along the
medium transport pathway 26. The continuous medium 24 may be
advanced (or retracted) in discrete steps, which may be of equal
step size or variable step size, and the time between the discrete
steps may be periodic or variable. In some embodiments, the time
interval between discrete steps may be so small such that the
advancement (or retraction) of the continuous medium 24 may be
effectively continuous. Similarly, in some embodiments, the
advancement (or retraction) of the continuous medium 24 may be
continuous.
[0096] At 1206, the controller subsystem 22 determines whether a
leading edge 32 of a label 30 is proximal to an edge (or bar 17) of
the label peeler 16 where the label is peeled from the release
liner. In some embodiments, the label peeler 16 may include a
sensor bundle 40 or 42 that detect labels in proximity to the edge
where the labels 30 are peeled from the release liner 29. In other
embodiments, the controller subsystem 22 may calculate that the
leading edge 32 of a label 30 is in proximity to the edge (or bar
17) where the labels 30 are peeled from the release liner 29. For
example, controller subsystem 22 may know the distance between a
scan point by one of the sensor bundles 40, 42 and the edge (or bar
17) where the labels 30 are peeled from the release liner 29, and
the controller subsystem 22 may calculate the distance traveled by
a label after the label or a portion of the label passes through
the scan point. If the leading edge is not proximal to the edge
where the labels 30 are peeled from the release liner 29, the
process continues at 1220, otherwise, the process continues at
1208.
[0097] At 1208, the controller subsystem 22 increases the tension
in the release liner 29. The spindle 21 of the medium take-up 20
may be driven with a DC motor though a transmission of a fixed
drive ratio. The controller subsystem 22 controls the spindle 21 to
wind up the release liner 29 and apply a tension on the release
liner 29. The increased tension in the release liner 29 facilitates
peeling the label from the release liner and also facilitates
pulling the continuous medium 24 through the print station 14.
[0098] At 1210, the controller subsystem 22 determines a change in
medium advancement rate caused by the increased tension in the
release liner. There is a desired or theoretical rate at which the
continuous medium 24 should advance through the medium transport
pathway 26. Pulling the continuous medium 24 through the print
station 14 by increasing the tension in the release liner 29
changes the rate at which the medium advances through the medium
transport pathway 26. The controller subsystem 22 may determine the
change in the medium advancement rate based upon information from
the sensor array 12.
[0099] At 1212, the controller subsystem 22 adjusts the medium
advancement rate to compensate for the pulling of the release liner
29 by the spindle 21. Typically, the controller subsystem 22 may
decrease the medium advancement rate. If the continuous medium 24
is being discretely stepped through the medium transport pathway
26, the controller subsystem 22 may decrease the step size or
increase the time interval between steps. If the continuous medium
24 is being continuously moved through the medium transport pathway
26, the controller subsystem 22 decreases the rate, i.e., change
the speed at which the continuous medium moves.
[0100] At 1214, the continuous medium 24 is advanced.
[0101] At 1216, the controller subsystem 22 determines whether the
trailing edge of the label is in proximity to the edge (or bar 17)
where the label is peeled from the release liner. In some
embodiments, the label peeler 16 may include a sensor bundle 40 or
42 that detect labels in proximity to the edge (or bar 17) where
the labels 30 are peeled from the release liner 29. In other
embodiments, the controller subsystem 22 may calculate that the
trailing edge 34 of a label 30 is in proximity to the edge (or bar
17) where the labels 30 are peeled from the release liner 29. For
example, controller subsystem 22 may know the distance between a
scan point by one of the sensor bundles 40, 42 and the edge (or bar
17) where the labels 30 are peeled from the release liner 29, and
the controller subsystem 22 may calculate the distance traveled by
a label after the label or a portion of the label passes through
the scan point. If the trailing edge is not proximal to the edge
where the labels 30 are peeled from the release liner 29, the
process continues at 1214, otherwise, the process continues at
1218. Typically, 1214 is repeated until the leading edge 32 of the
label 30 is beyond the edge (or bar 17) where the labels 30 are
peeled from the release liner 29 and only a small portion of the
label 30 remains attached to the release liner 29.
[0102] At 1218, the advancement of the continuous medium 24 is
paused until the label that has been partially peeled from the
release liner is taken away. Typically, a label applicator (not
shown) takes the label from the release liner and applies the label
to an object (not shown).
[0103] At 1220, the controller subsystem 22 determines whether the
end of the continuous medium 24 has been reached. If the end of the
continuous medium 24 has been reached, the process ends at 1222.
Otherwise, the process returns to 1204.
[0104] The above description of illustrated embodiments, including
what is described in the Abstract, is not intended to be exhaustive
or to limit the embodiments to the precise forms disclosed.
Although specific embodiments of and examples are described herein
for illustrative purposes, various equivalent modifications can be
made without departing from the spirit and scope of the disclosure,
as will be recognized by those skilled in the relevant art.
[0105] For instance, the foregoing detailed description has set
forth various embodiments of the devices and/or processes via the
use of block diagrams, schematics, and examples. Insofar as such
block diagrams, schematics, and examples contain one or more
functions and/or operations, it will be understood by those skilled
in the art that each function and/or operation within such block
diagrams, flowcharts, or examples can be implemented, individually
and/or collectively, by a wide range of hardware, software,
firmware, or virtually any combination thereof. In one embodiment,
the present subject matter may be implemented via Application
Specific Integrated Circuits (ASICs). However, those skilled in the
art will recognize that the embodiments disclosed herein, in whole
or in part, can be equivalently implemented in standard integrated
circuits, as one or more computer programs running on one or more
computers (e.g., as one or more programs running on one or more
computer systems), as one or more programs running on one or more
controllers (e.g., microcontrollers) as one or more programs
running on one or more processors (e.g., microprocessors), as
firmware, or as virtually any combination thereof, and that
designing the circuitry and/or writing the code for the software
and/or firmware would be well within the skill of one of ordinary
skill in the art in light of this disclosure.
[0106] From the foregoing it will be appreciated that, although
specific embodiments of the invention have been described herein
for purposes of illustration, various modifications may be made
without deviating from the spirit and scope of the invention.
Accordingly, the invention is not limited except as by the appended
claims.
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